84889-09-8Relevant articles and documents
Two approaches for the engineering of homogeneous small-molecule hydrogels
Ding, Baiyong,Li, Ying,Qin, Meng,Ding, Yin,Cao, Yi,Wang, Wei
, p. 4672 - 4680 (2013)
Small-molecule hydrogelators have been widely used to engineer supramolecular hydrogels for biomedical applications. Typically, a change of the solubility of small molecules in solvent is used to trigger the gelation process. This requires a switch of pH or solvent by mixing two different types of solutions. However, due to the intrinsic ragged free energy landscape that underlies the self-assembly process and the high viscosity of the solution that limits the diffusion, the hydrogels made by these methods are often limited by their inhomogeneity and irreproducible physical properties. It is therefore desirable to circumvent these drawbacks and produce homogeneous hydrogels. Conversely, only a few studies have been done towards this direction. In this article, we present two novel approaches to engineer homogeneous hydrogels. One is based on the nano-dispersed colloids to hydrogel transition and the other is based on the decomposition of potassium persulfate to mildly change the pH. These two methods allow kinetically controlling the self-assembly process and the resulting hydrogels are indeed more homogeneous and reproducible. Moreover, the structural and morphological characterizations suggest that the structures of the hydrogels prepared by different approaches are distinct from each other, leading to diverse macroscopic mechanical properties. These results suggest that besides the thermodynamics, the self-assembly kinetics also plays an important role in determining the properties of the final assembled hydrogels. We propose that it is possible to rationally tune the physical properties of the hydrogels by simply control the self-assembly kinetics without changing the structure of the small-molecule hydrogelators.
Benzoisothiazolone (BIT): A Fast, Efficient, and Recyclable Redox Reagent for Solid Phase Peptide Synthesis
Bukya, Hemalatha,Gangireddy, Pavankumar,Mainkar, Prathama S.,Nayani, Kiranmai
supporting information, p. 5358 - 5362 (2020/08/27)
Solid-phase peptide synthesis (SPPS), a preferred synthetic procedure, generates by-products and effluents in multiple equivalents for one equivalent of desired product. Presented herein is the use of a fast and efficient coupling protocol for SPPS using a benzoisothiazolone (BIT), which can be fully recycled. The BIT, as redox activator, works under very mild conditions and generates minimal amount of waste. As a case study, the BIT coupling protocol is applied to the synthesis of side chain of the recently discovered antibiotic, teixobactin.
A catalytic one-step synthesis of peptide thioacids: the synthesis of leuprorelin via iterative peptide-fragment coupling reactions
Matsumoto, Takuya,Sasamoto, Koki,Hirano, Ryo,Oisaki, Kounosuke,Kanai, Motomu
supporting information, p. 12222 - 12225 (2018/12/01)
A catalytic one-step synthesis of peptide thioacids was developed. The oxygen-sulfur atom exchange reaction converted the carboxy group at the C-terminus of the peptides into a thiocarboxy group with suppressed epimerization. This method was successfully applied to the synthesis of the peptide drug leuprorelin via an iterative fragment-coupling protocol.
Fmoc-Amox, A Suitable Reagent for the Introduction of Fmoc
Kumar, Ashish,Sharma, Anamika,Haimov, Elvira,El-Faham, Ayman,De La Torre, Beatriz G.,Albericio, Fernando
, p. 1533 - 1541 (2017/10/25)
Synthesis of most peptides is achieved using solid-phase peptide synthesis employing the Fmoc/tert-butyl strategy. However, the introduction of Fmoc in N-unprotected amino acids seems to be challenging due to the formation of dipeptides and sometimes tripeptides as impurities and β-alanyl impurities when Fmoc-OSu is used as well. Herein, we report an efficient and successful method using Fmoc-Amox, which is an oxime based derivative, toward the synthesis of Fmoc-glycine with no traces of side reactions. Fmoc-Amox is inexpensive, and Amox can be easily removed after the reaction, thus affording pure Fmoc-Gly-OH devoid of any detrimental impurities or contamination, mainly dipeptide or Amox itself, as shown by high-performance liquid chromatography and NMR, respectively.
